1. Technical Field
The present invention is directed generally to a carton tray with a new corner post construction and the method of forming the tray. Specifically, the invention is directed to an improved carton formed from blanks which may be shipped flat on pallets to a customer location where the cartons may be assembled on a customer's forming machine into strong, attractive cartons without exposed raw edges on the exterior corners.
2. Description of the Prior Art
Oftentimes, tray forming of folding cartons can be objectionable to users requiring a high degree of structural aesthetics and vertical stacking strength. Common glue-forming of trays employs four Britewood style corner posts bonded inside to either the side panels or end panels. When this type of carton is viewed at eye level, the resulting outside corner always shows a die-cut raw edge.
One way around this is full gusset style forming. A gusset no longer exhibits this raw edge but requires that the paper board be coated on both sides with a heat sealing medium or requires that the glue forming be fairly complicated and expensive. In both cases, the gusset must be bonded to itself and then bonded inside the carton body.
Gusset or bellows corners have been designed in the past so the bonding medium on only one side of the substrate can bond the gusset only to the side panel of the carton. This is difficult and doesn't allow for bonding the gusset to itself. The gusset bonding to the side panel is marginal at best.
Bellows have been designed in the past to provide a carton corner construction but through bonding to a flange and usually to the outside of the carton only. A secondary risky and difficult design is where one side of the gusset is cut down slightly.
Setup cartons have been prepared in the past which are strong and present no die-cut raw edges but these are extremely expensive because they are overwrapped with a printed glued-on paper and are shipped fully assembled and empty. Simplex trays have been designed which may be shipped flat and manually or machine assembled by folding a double thickness end panel over fully gusseted folding corners with locking tabs to hold the assembled corners together but gaps are often formed in the assembled corner and much paperboard is required or wasted for the double side panels and end panels required for a simplex tray.
Accordingly, there is a need for an improved carton construction and method of forming same which enables carton blanks to be shipped flat for simple assembly on a customer's forming machine with adhesive applied to only one side of the carton blank and with multi-ply strong corners which exhibit no die-cut raw edges.
Accordingly, a primary object of the invention is to provide an improved carton tray and method for forming same which enables formation on simple machinery yet which provides an aesthetically pleasing and strong corner construction.
Another object is to provide such a carton tray and method which makes efficient use of the paper board stock from which it is formed.
Another object is to provide such a carton tray and method of forming same which provides such an inherently strong corner construction that the caliper of the paperboard blank may be dropped without sacrificing stacking strength compared to higher caliper trays of known construction.
Another object is to provide such a carton tray and method of forming same which enable blanks to be shipped flat on pallets to a customer location where the cartons can be fully assembled on the customer's forming machine with application of adhesive to only one side of the cartons.
A related object is to provide such a carton tray and method of forming same which enables assembly on standard hot melt glue forming machines.
Finally, an object of the invention is to provide an improved carton tray which is simple and rugged in construction, economical to manufacture and efficient in operation.